\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{tikzpicture}[>=latex,scale=1.0]
  % \useasboundingbox(-2,-2.2)rectangle(2,1.5);
  \draw[double,double distance=3pt,rounded corners=5mm](-1.3,-0.5)rectangle(1.3,0.5);
  \draw[pattern=north east lines](-2,-0.05)node[below right]{$+$}rectangle(-0.6,0.05)(0.8,0.05)rectangle(2,-0.05)node[below left]{$-$};
  \draw(0.7,-0.15)rectangle(0.8,0.15);
  \fill(0.6,-0.1)rectangle(0.7,0.1);
  \draw(-0.6,0)to[bend left=10](0,0)to[bend right=10](0.6,0);
  \draw[thin](0,0)--(-130:0.8)node[below]{触丝};
  \draw[thin](-0.4,0.5)--++(120:0.3)node[above]{管壳};
  \draw[thin](0.6,0.08)--++(110:0.7)node[above]{PN 结};
  \draw[thin](-1.5,0.01)--++(120:0.3)node[above]{引线};
  \draw[thin](1.5,0.01)--++(60:0.3)node[above]{引线};
  \end{tikzpicture}
\end{document}